Evaluation of marginal seal of different composite restored class V cavity preparations with different cavosurface margins

Abstract

Purpose The aim was to evaluate and compare the marginal seal of Class V composite restored with different cavosurface margins. Materials and methods A standardized Class V cavity, 4 mm wide, 3 mm high, and 3 mm deep, were prepared on the buccal surface of 60 extracted molars with the occlusal margin located in enamel and the gingival margin located in dentin-cementum 1.0 mm below the cementoenamel junction. The teeth were divided into two main groups: group I, cavosurface angle was 90° butt-joint; group II, beveled enamel and dentin cavosurface margins. Each group subdivided into three subgroups: group A, restored with Filtek bulk-fill flowable composite. Group B, restored with Filtek bulk-fill posterior composite. Group C, restored with Filtek Z250XT Universal composite. Restorations were cured with LED light curing unit. All specimens were stored in 37°C and 100% humidity for 24 h, thermo cycled for 600 cycles with baths held between 5 and 55°C, a dwell time of 30 s and a transfer time of 10 s. The restored coronal portion were cut 3 mm beyond the cementoenamel junction, each specimen were sectioned in bucco–lingual direction through the center of each restoration resulting in two sections. The cut surfaces were examined at the occlusal and gingival margins using a stereomicroscope at 30× magnification with an attached digital camera. Results There was significant difference in microleakage between the three tested materials where flowable bulk-fill showed a lower degree of microleakage than posterior bulk-fill and conventional composite at P value of less than 0.05 and there was a degree of significant in microleakage at occlusal and gingival margin where occlusal margins showed the a lowest degree of microleakage. Conclusion There was significant inverse correlation between flowable bulk-fill and conventional composite and high significant between occlusal and gingival margin and there is no need for a bevel in Class V carious lesions.